package com.ecut.xzh.interceptor;

import com.ecut.xzh.constant.JwtClaimsConstant;
import com.ecut.xzh.context.UserHolder;
import com.ecut.xzh.exception.ServiceException;
import com.ecut.xzh.properties.JwtProperties;
import com.ecut.xzh.utils.IpUtil;
import com.ecut.xzh.utils.JwtUtil;
import io.jsonwebtoken.Claims;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * jwt令牌校验的拦截器
 * @author XZH
 */
@Component
@Slf4j
public class JwtTokenUserInterceptor implements HandlerInterceptor {

    @Resource
    private JwtProperties jwtProperties;

    /**
     * 校验jwt
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //判断当前拦截到的是Controller的方法还是其他资源
        if (!(handler instanceof HandlerMethod)) {
            //当前拦截到的不是动态方法，直接放行
            return true;
        }

        // 获取访问者的IP地址
        String ip = IpUtil.getIpAddress(request);
        log.info("访问者IP地址：{}", ip);
        if(!IpUtil.isChineseIp(ip)){
            return false;
        }

        //1、从请求头中获取令牌
        String token = request.getHeader(jwtProperties.getUserTokenName());

        //2、校验令牌
        try {
            log.info("jwt校验:{}", token);
            // 如果token为空或错误，则返回401
            Claims claims = JwtUtil.parseJWT(jwtProperties.getUserSecretKey(), token);
            Long userId = Long.valueOf(claims.get(JwtClaimsConstant.USER_ID).toString());
            log.info("当前用户id：{}", userId);
            //将用户id放入存储空间，到service层再拿出来
            UserHolder.setCurrentId(userId);
            //3、通过，放行
            return true;
        } catch (Exception ex) {
            //4、不通过，响应401状态码
            response.setStatus(401);
            return false;
        }
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // 移除UserHolder中存储的用户信息，防止内存泄露
        UserHolder.removeCurrentId();
    }
}
